Flexible bellows



Dec. 11, 1951 T. H. NAKKEN FLEXIBLE BELLOWS Filed April 1, 1948 INVENTOR. THEOPOKEHINAKIiZZ/W Patented Dec. 11, 1951 UNITED STATES PATENT OFFICE FLEXIBLE. BELLOWS" Theodore H. Nakken, New York, N. Y.

Application April 1, 1948,, Serial No. 18,453

4 Claims.

This invention relates to improvements in flexible bellows and has for a principal object, the provision of bellows of greater flexibility than has heretofore been possible.

Another object of the invention is the provision of fabricated flexible bellows adapted to be extended a greater amount, and having a minimum number of flanges.

A further object of the invention is the provision of fabricated metallic bellows in'which the fatiguing of the metal, from which the bellows are formed, is reduced to a minimum.

Yet another object of the invention is the provision of fabricated bellows adapted to be easily manufactured on a. massproduction basis at a lower cost than fabricated bellows of the prior art.

These and other objects of the invention will be readily apparent to those skilled in the art, upon perusal of this specification and the accompanying drawing.

Referring now to the drawing, which is merely .given by wayof example to illustrate the invention, a cross sectional elevation of one type of bellows made according to the invention is shown. Referring to the drawing, it will be noted that the bellows shown is built up'or fabricated from -two differently formed types of diaphragms, one

designated as A and the other asB, and these diaphragms are alternated with sealing means between the junctures of the flanges of said diaphragms. The flange A consists of a circular metallic disc is with a circular hole H in the center formed from a fiat sheet of metal, or any l0, when formed, is cupped so that when assembled with a diaphragm of the type B, a spac l3is formed therebetween. The edge l4 about the circular opening H in the center is made in I the form of an annular U-shaped channel, by

way of example, and thisshaping may be accomplished in the same operation as the formation of a rolled edge l2, for example, in a press of proper design.

The diaphragm B, designated by the numeral I5, is in the form of a fiat disc, the outer edge It of which is also shaped in the form of a U-shaped channel. The disc l5 has a central offset portion I] with a circular hole therein and the edge 8 bounding this hole is rolled or headed, for

f example, somewhat like the edge l2 formed on the diaphragm A.

Many diaphragms of both types may be made up, and in assembling them, they are alternately disposed in interlocking relation, as will now be explained. In the two types of diaphrag'ms, the respective dimensions should be such thatthe rolled inner edge ll! of the diaphragm B easily and loosely fits in the U-shaped inner edge I4 of the diaphragm A. Likewise, the. rolled-over outer edge I! of the diaphragm A loosely fitsinto the U-shaped channel l6 formed on the outer edge of the diaphragm B. These fits should be such that it is possible to place a sheet of resilient sealing material, such as rubber, artificial'or synthetic rubber, or any other sealing material which can be punched out in the form of rings, between them. This is done by positioning the ring sealing material R in the U-shaped channel of one diaphragm, for example, the channel I 4 of the diaphragm A, after which the rolled edge of the B type diaphragm, for example, the rolled edge ill, will make a snug fit in this channel.

Likewise, ring R of the sealing material is placed in the U-shaped channel of the last mentioned type diaphragm, for example, the channel It, and the rolled for beaded edge of the other type diaphragm,,for example, therolled ed e [2 of the diaphragm A may be placed therein with a snug fit;

In order to fabricate a complete bellows, sev- 'eral diiferent procedures may be followed, of V which the following isindicated by way of example.

Diaphragms of the two types are assembled in pairs in such a manner that first the inner edges, for example the edges l4 and H, are joined together with resilient rings of the inner edge diametenfor example the rings R are used. A ring of this type is placed in the U-shaped inner edge channel M of the diaphragm A and then the rolled edge l8 of the diaphragm B is placed on top oftheresilient ring and pressed downwardly sothat the beaded or rolled edge l8 now vfits the U-shaped channel l4 closely. Ifhe two diaphragms, so, assembled, are then placed into a proper. tool jandjthe" free upright edge of; the U-shaped channel I4 is rolled over so asto firmly embrace both the beaded edge l8 and the interthediaphragms are'assembled in pairs, the B diaphragms are foremost. Now, starting in with one pair which has been so assembled and with the type B diaphragm foremost, a resilient ring R (or larger diameter than the rings R) is placed in the U-shaped channel IE. The operator then picks up another pair which has been previously assembled and places the curled or rolled edge I2 against the resilient ring R, and presses downwardly, with the result that the portion l2; the resilient ring R and the curled or rolled edge I! form a close fit when pressed downwardly. Thereafter, the upright edge of the U-shaped channel I 6 on the diaphragm B is rolled or spun over the rolled or beaded'rim i2 of the diaphragm A and the resilient ring of rubber or the like, in a manner similar-"tethefirst rolling-over process described. It is also true that this operation may be effected by spinning, pressing, or in any other suitable-manner.

The assembly may be continued in the same manner and eaclr time a pair of diaphragms is added: to the stack being: formed,-. a. workable bellows section: is formed; The process may be carried on until the. numberofflanges. or sections desired for the particular type of bellows being manufactured have been included; in the assem- Although the diaphragm A is shown as having the greater portion of its radius outside of the inner'rolled edges, and. although the diaphragms B have the greater portion of: their radius inside of. the: outer rolled edges; it will be understood that the diaphragmsmay be formed in any manner desired without departing from the spirit of the invention. As' an example of this, the dia- -phragms may be: formed with concentric corin metals which have been bent repetitively. As a matter of fact, longitudinal motion of my bellows will manifest itself in the edges of the diaphragms as rolling actions of the beaded edges with respect to the rolled-over outer edges, the rolling action taking place within the resilient material. The only stresses to which the metal forming the diaphragms are subjected, occur in the corrugations which may be placed concentrically in the metal; but here the action will be very slight and will never approach the elastic limit of the material from which the diaphragms are made, if the design of the bellows has been executed properly.

One of the greatest advantages of my method of assembly herein described is that it is possible, at will, to fabricate the bellows (a) for expansion purposes (b) for compression only, or

' (c) for both contraction and expansion purposes.

-sidered that itis. possible to'vulcanize the redi'aphragms and the resilient rings is a very close i one and it is almost impossible to separate one from the other, so that the entire bellows structirre becomes a fluid-tight, integral unit of great strength and flexibility. The strength governed primarily by the strength of the metals used in the diaphragms and which surrounds the resilient material both at the inner and outer diameters, for example H at the inner diameters and [Gat the outer diameters.

tight joint is formed at both the inner and the outer edges of each section. of the bellows.

It will be clear from the above that the bellows assembled in this manner shows a marked freedom of motion and, can be extended to a far greater. degree than bellows made of metal alone.

The action of. my new and improved bellows is governedlargely by the degree of compliance of the interleaving ring material (R and R) y flexing otthismaterial will take place infshear and it is well known that rubber flexed in shear is subject very slightly, if at all, to the phenomenon known as fatigue, which.is so apparent This feature becomesapparent when it is consilient material after assembly in any desired position ofrthe assembled bellows.

If the resilient material is of the proper compound; the bellows will always return to the position in which the vulcanizing process was carried out. It is obvious that the snappiness oi the return action may be increased by means of a suitable. spring arrangement devised to urge the bellows in the desired direction when the same is mounted for any particular use. It will also be apparent that the end diaphragms or plates of the bellows may be mounted in almost any manner. desired. They may take many forms or may be shaped. to any shape necessary for the purpose for which the bellows. are to be used, and they may be soldered to the bellows or rolled in connection therewith in a manner similar to the method described herein above with resilient material: bonded to the'diaphragm and the end plate.

The system of bellows" shown in the drawing maybe rapidly assembled in the following manner.

The diaphragms l0 may be formed by curling the outer edges I2 of. the discs and by curling the iner edges ll partway. In other words, instead of first curling them in the form shown in the drawing, they would be curled half way, leaving the free edge from the center of the curve upwardly straight.

Thediaphragm l5 would have its inner edge l-8 curled as shown and the outer edge I6 would be curled so that the free edge from the center of the curve upwardly would be straight.

Then, the discs would be assembled in pairs by placing a ring of rubber-like material within the partially curled inner edge Id of disc in and then placing the curled inner edge l8 in contact with the rubber-like material R and then finishing curling the edge H until it assumes the form shown in Figure 1. A number of these. pairs may 'be so assembled and the rubber-like material nated. In such bellows of the prior art, wherein a metallic bond is established between the discs forming the bellows, the flexing of such bellows causes strains in the metal adjacent to such metallic bonds which after a comparatively few expansions and compressions of the bellows produces fatigue in the material. My bellows, constructed in accordance with the present invention, have no such strains and consequently have almost unlimited life, without appreciable fatigue.

Although I have herein shown and described by way of example a preferred embodiment of the invention and a modification thereof, it is obvious that many changes may be made in the arrangements shown and described within the scope of the following claims.

What is claimed is:

1. In a flexible bellows, a plurality of metallic diaphragms having their outer and their inner edges terminating the arcuate portions in excess of 180, said diaphragms being in two series, one

series in which the diameter of its arcuate por-' tion of its inner edge is larger in diameter than the arcuate portion of its outer edge, and another edge interlocked with one of its neighbors and having its inner edge interlocked with the other of its neighbors on the other side thereof, and

flexible sealin means between each such interlock.

3. In a flexible bellows, a plurality of annular diaphragms, each having both its inner and its outer edges arcuate in form, its inner edge being in interlocked relation with the inner edge of one of its adjacent neighbors and its outer edge being in interlocked relation with the outer edge of its other adjacent neighbor, and flexible plastic sealing means between each such interlock.

4. In a flexible bellows, a plurality of annular metallic diaphragms, each having its inner and outer edges arcuate in form and disposed in an array of interconnected pairs, each of saidpairs having corresponding arcuate edges of the diaphragms thereof interlocked, the interconnections between said pairs being comprised of other corresponding interlock arcuate edges of neighboring diaphragms, and flexible plastic sealing means between and bonded to the adjacent surfaces of each such interlock.

THEODORE H. NAKKEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

